Arrangement in grinding machines



Oct. 26,1948. I N K. w. .1. HJELMBLAD 2,452,123

ARRANGEMENT IN GR INDING MACHINES Filed Feb. 14, 1945 3 Sheets-Sheet 1 v INVEIV'I'OR M/l/MMW Get. 26,1948 K W. IHJELMBLAIID KRRA-NG'EMENT IN GRINDING MACHINES Filed Feb. 14, 1945* 3 Sheets-Sheqti lwavralv we WWW Patented Oct. 26, 1948 UNITED TATE-S PATENT OFF-ICE ARRANGEMENTIN GRINDING MACHINES 'llfiarl-iwilhelmJosefiHjelmblad, Alstemswe'den Application February 14, 1945, Serial No. 577,740 In Sweden March 4; 1944 fi Claimsi "The present invention relates to a grinding machine, wherein an adjustable lead unit is adapted to control thatrelative movement of a member carrying the leaduni't; on the one hand,

and the grinding tool, on the other hand. through which-the surface tobe ground or the edge of the work piece and the operating surface ofthe grinding tool are moved-along "one another to perform the grinding operation. Through the lead unit the work piece will have imparted thereto a'positive-gui'dan'ce by-which'th'e work piece andthe'g'rinding tool are'move'd in the'proper manner relatively'to each other to obtain the desired grinding result.

The arrangements hitherto employed to effect a positive'guidance-ofthe work'- piece and the grinding tool show a number of drawbacks. In known grinding machines with 'a'lead unit'in the sense here implied, the adjustment of the lead unit to adapt the movement of the workpiece to the'shape'of'theedg'e of the'work piece to'be ground is complicated"andtime-wasting, inasmuch as it "generally requires a" plurality "of tedious adjusting operations;

According to the invention, the lead unit is not I adjustedby reference tograduated' scalesbut is adjusted according to the work'piec'e'itself, The mechanism for transmitting motion between the sine "bar of the lead unit and the Work carrying spindle includes two relatively adjustablelmem' bers which form a dividing'or indexing unit of known type 'by which the" spindle is adjusted angularly to present different areas, forexample the several cutting 'edges'of a drill or milling cutter; to the grinding tool. The'new method of adjusting the sine bar from the-work pieces itself is made possible'by the'provisi'on of latch mechanism for temporarily locking one member ofthedividing unit tothe movable carrier in a predetermined" initial position, and by so constructing-the lead unit that'the motiomtransmitting mechanism can be adjustedto aniniti'al neutral'relationship in which the time bar may bemoved angularly without efiectin'g any'movement of the motion-transmitting -mechanism.- The manner in-which these predetermined initial settings may be *employed'to adjust the s'ine'bar of the lead unit Willbe' described-in detail hereinaiter.

According tothe'invention, theleadunit isso constructed as to have aposition'fth'e initialpo'sition, in which the member carrying the work piece during the grinding operationremains unactuated "at analter'ation of the adjustment' of the-: lead unit to-provide for adaptation to the v the workpiece.

2 .1 shape of the edge or surface of the-workpiece to be'ground; Thus there will aways be a definite initial'position of the lead 'unit, according to which the member carrying the work piece may be adjusted. The lead unit may be-in such -motion-tranmitting connection "with-the membe'r carrying the work piece that'the initial'position of the lead unit corresponds to a definiteposition of said member. The"motion-transmittingconnection may comprise adjusting members faci'li tating -an accurate adjustment of' thework piece relatively tothe initial position oftlie leadunit. According to the invention} it is possible' to adjust the lead unit to'th'e *sl'iape of'the edge tdbe ground; so that the lead unit willinthe-subsequent grinding operation guide the work piece relatively to the grinding disk in exact correspondence to' the shape of the edge.

Agreat variety of work pieces may-be'ground in a grinding machine according'to the invention, butthe invention involves special advantages in the grinding of toothed tools, such as cutters, reamers and the like with obliquely cut teeth, although the invention is also applicable to straightteeth. As an example to facilitatean understandingof'the description of the" invention, the Work piece is taken to con'sist of a cylindrical cutterwithpbli'quely cut teeth. Expressions such as the shape of the edgeorsurface of'the'work piece to be ground as used in the precedinglparagraphs, in a cutter of this'kind refer'to the peripheral shape-and pitch of the cuttertooth; It is conceivable within the scope ofthe'inven tion to arrange the grinding'tool(thejgrin'ding disk). in such..mann'erthat' the grinding'tooi is adjusted'and'guidedby the lead unit, so that" it will-move along the tooth of the work piece during the grinding operation, which work piece may then be stationary relatively tothe"machine frame, but since the grinding toolrnu'st also have its operating movement (rotation'inthe case of a grinding disk), it will be found simpler to"provide the adjustability' in the member carrying In a corresponding"form of em bodiment, said Work iece is thereforeprovide'd with a plurality of parts adjustable-relatively"to eachotheraboveall an operating spindle,- on which the work piece maybe clampedfandn head in which the operating spindle is mounted. The head may be secured to a" table which is movable along a'rectilinear guide, and the operating spindle is turned by a drive from the lead unit, when the'table is moved along itsfrectilinear guide during the grinding operation; "The movement of the work piece during the grinding operation ma thus be regarded as being com- 'posed of the rectilinear movement of the table and the rotary movement of the operating spindle.

An example of the application of the invention is illustrated in the accompanying drawings. Fig. l is an endwise view of a universal tool grinding machine to which the invention is applied. Fig. 9 is an elevation of a detail of the machine. Fig. 3 is an elevation to a larger scale, partly in section through the dividing head of the machine. Fig. 4 shows a section on line IV-IV in Fig. 3, and Fig. 5 is a horizontal section on line V-V in Fig. 4. Figs. 6 and 7 are diagrammatic views of the lead unit and the spindle with the work piece in two positions of adjustment and have for their object to illustrate the mode of adjustment.

In the drawings, 1 designates the machine frame with a standard 2 adapted to be raised and lowered, said standard carrying the grinding tool, which here takes the form of a rotary grinding disk 3.- The frame carries a, transverse slide 4, which is displaceable in a manner known per se by means of a hand wheel, not shown, in a direction toward and from the grinding disk 3, said slide supporting a table 5, which is displaceable by means of a hand wheel, not shown, in a directionatright angles to the direction of movement of the transverse slide 4. Secured on the table 5 is a plate 6 adapted rotatably to support an angular piece 1 arranged to be locked thereto, said angular piece having, in turn, a dividing head 9 rotatably secured thereto, which head is adapted to'be-locked in said angular piece and carries a hollow spindle ,9, onto which, a tool Ill as indicated by chain-dotted lines may be clamped in a manner known per se-by means of a rod [2 extending through the central hole I I of the spindle 9. The spindle 9 carries a gear Wheel 13 freely rotatable thereon, the hub Id of said gear wheel being provided with a flange l5, to which is exchangeably secured a dividing plate IS with dividing apertures H H I1 and so forth and with'alocking aperture l8 adapted to receive a latch 19. arranged on the dividing head 8, when the dividing plate is in its zero position. Freely rotatable on the spindle 9 is a carrier disk 2i with; a graduation 20, said carrier disk being adapted to be locked to the spindle 9 by'means of ahandle 22. The carrier disk 2| is provided with a stop pin 23, which is adapted to engage the dividing apertures I! so as to couple the carrier disk to the dividing plate in different relative angular positions.

The, dividing head 8 is provided with a handle 24150100]; the spindle 9 t0 theghead. The dividing head 8 also has a toothed rack 25 vertically displaceable therein, said rack engaging the gear wheel l3 and being displaceable by means of a lead unit. The latter consists of a supporting roller 26 arranged on the lower end of the toothed rack and engaging a guide slot 21 in a guide bar 28. The guide bar is displaceably mounted in an attachmentZQ, which is secured toa holder 3| by means of a journal 30 so as to be swingable in the vertical plane, said'holder being arranged on the transverse slide 4 and adapted to be displaced at right angles to' the direction of movement of thisslide. The guide bar 28 is adapted to be locked to its attachment 29 by means of a handle 32, while the attachment 29 is adapted to be locked to the holder 3| by means of a handle 33 and the holder 3| is adapted to be locked to the transverse. slide 4 by means of ahandle 34.

fIhe mode of operation of the arrangement is as follows, for instance in the grinding of a spiral cut cutter or reamer:

The work piece, i. e. the cutter I0, is clamped in any suitable manner in the spindle 9 of the dividing head 8, whereupon the spindle 3' (see Fig. 2) of the grinding disk 3 is adjusted into the proper vertical position relatively to the spindle 9 of the dividing head 8 by the standard 2 being raised or lowered. The table 5 is moved in such manner that the supporting roller 26 on the toothed rack 25 will be situated opposite the shaft 30. In other words, the centre of that member, the supporting roller 28, through which the transmission means formed by the toothed rack 25 and the gear wheel 13 is in engagement with the guide bar, will in this position be on the axis of rotation of the guide bar 28 (compare Fig. 6). In said position, a swinging movement of the guide bar about the centre line of the shaft 30, for instance from the position shown by full lines into the position indicated by chain-dotted lines in Fig. 6, does not entail any movement of the toothed rack 25 and, consequently, the angular position of the work piece I9 also remains unaltered atsuch swinging movement. In said position of theguide bar and the roller, that is to say in the initial or neutral position of the lead unit, the aperture I8 of the dividing plate l6 secured on the gear wheel I3 will be opposite the latch l9 which engages into and locks the dividing plate to the dividing head 8. The dividing plate will thus be in a zero position corresponding to the initial position. The work piece is now to be adjusted into a corresponding suitable initial position. To this end, the spindle 9 and the work piece l0 carried thereby are released from the dividing head 8 by loosening of the handle 24 and the carrier disk 2| is released from the spindle 9 by loosening the handle 22. The released spindle 9 is now turned so that a suitable point a on the edge of a tooth l0 (Fig. 6) of the cutter in will be situated at the proper level, for example as high as the centre line of the spindle 9,for engagement by thegrinding disk 3. .In the case of a straight cylindrical grinding disk, this level is also as high as the centre line of this disk as previously adjusted to the level of the centre line of the spindle This adjustment may be efiected with the aid of an indicator of any suitable kind adapted exactly to indicate the level of the spindle centre. In Figs; 6 and 7, this indicator takes the form of a device including an indicator dial 40, which is to be secured to the machine frame or, in the case of a grinding disk with an adjustable bearing holder, to this holder by means of a swingable arm, by which it is kept in the indicating position in such manner that its pointer 4| points at zero or some other known position when the ball 43 of the indicator rod 42 has its bearing point located exactly on a level with the centre line of the spindle 9. The carrier disk 2| which is now free from the spindle is adjusted into the zero position by the stop pin 23 being introduced into the aperture ll of the dividing plat l6 previously adjusted in the zero position, whereupon it is locked to the spindle 9 by means of the handle 22. The spindle with the work piece, the carrier disk, the dividing plate and the lead unit now take the proper initial positions relatively to each other and are maintained in these positions. It should be noted that the table 5 carrying the spindle cannot be displaced in the longitudinal direction of the spindle, since this is prevented by the obliquely positioned guide bar. Only if,

masseuse the flatter is; adjusted 1 .=in :parallel ntozcthe 1 axial diifigliiQIIrQffthEr spindle; zorithe direction inx-which the. table .5: ,is.-. guided on the ctransuerse i slide; dl willisuch gmovementcbes possible when the :latch :lBais, f aS; specified above, inflocking; engagement withthe-dividingiplate.

. It-znow remains toiimpart Etotheguide, rail .the inclination .corresponding .2110 :the inclination. III the tooth ID on the tool ormore ,generallyex pressederto. adapt. :the. tadiustment: of :the; lead unit. toatheshape of :the itOQthl. To-this end,- :the latched) is;first disconnectcdatozpermit the spin l Brand 'the parts coupled; thereto to .-.move ifr-eely. Furthermore, the handle. 3.3: .is loosened, so :that the attachment 2.9:- of :the guide rail. :B-Baandcthus the guide rail .may iturn about. the shaft .30 The table 5 is now displaced, so that another point I) of the tooth I11 '-is broughtinto contact with the ball 43 Qfithc n icator, aswiHappearirom Fig. '7.' By turning the carrier disk 2! coupled to the dividing plate lfi by means of the stop pin 23, the spindle-9 is now *"turned-sothat the point I) of thetopth will be situated eng the same level as in;the-,first indication, that isstosay so;th at,the indicator pointer M is returnedzto zero-.-;Tdiis turningpmovement of the-sp indl eril'and workpiece l il can be readily effected since the pinion lfi: and rack 25 constitute a two;w ay motion-transmitting connection between the work spindle and the guide rail when the latterisreleased for angular addustment by Y turning the; lhailldlfir At lthe completion of gtheturning of carrier; disk ZzI-jby: stop pin; :23; the several elements ail-51in the. positions shown; n its and it will appear from the: end projections of the Work piece shown to the right in Figs. 5 and '7 by how great an angle the work piece has been turned. At the displacement of the table 5, the toothed rack 25 obviously followed in the movement, and the supporting roller 26 was then carried along the guide rail 28 to a position spaced from the shaft 30. At the turning of the spindle by means of the carrier disk for the adjustment of point I) to the proper vertical position, the toothed rack and the supporting roller therefore adjusted the guide rail 28 into the proper position corresponding to the inclination of the tooth l, whereupon the guide rail is to be locked by means of the handle 33. Now, the guide rail has the proper angle of adjustment relatively to the cutter tooth, so that the spindle 9 will be adjusted angularly upon displacement of the table to bring all parts of the tooth in the longitudinal direction thereof contact with the grinding disk at the same level.

During the grinding operation, the table 5 is moved to and fro, the toothed rack having then imparted thereto a movement up and down, which is transferred to the spindle and to the work piece through the gear wheel, the dividing plate and the carrier disk. Apertures of the dividing plate are disposed in correspondence to the teeth of the work piece. When a tooth is ground, no other adjustment is called for prior to the grinding of the next tooth than that the stop pin 23 is moved from the hole I1 to the hole H in the dividing plate, the carrier disk 2|, which is still locked to the spindle 9, being thus caused to turn the latter and the work piece by a corresponding angle, so that the new tooth will be brought into the proper position relatively to the grinding disk. The grinding of this tooth then proceeds in the same manner as the grinding of the first tooth.

The arrangement described also involves the advantage that the work piece may be adjusted exactly for the grinding of any desired clearance 6. angles .Qft theriieethz. siqmay cberefiedtedsswith the. ai'dliof :the. icarrieredisk;.ion the graduation-r21] of which ".theyadjusted angler; can; be easily mead off. The adjustmenttissefiecte'd so 'thatrtheatable 5 is displaced until theroarrierz diskrisa'in 3131518 (ii-position, fwhereupon; the Y dividing: plate:- il 61 is controlled by. the 1 latch: 1 951 and the: :spindle- 9'- locked by :means of: the, handle 124. The "carrier disk 2| is loosened from; the dividingrplate. 1:6 by :the: stop pin-.- '23.;yhell1gv withdrawn: and: from the spindle. by'smeansaoi the handle 22 and;:is; now turned in la countereclochwise direction; :Eig. .1,.'by the number of degrees desired for'the clearance angle, -and...is;again lockedrto the:=spind1e 9.: .The spindle 9 is released by means of; 'theihandlefld; whereupon: th'eicarriers disk: 2] 'is, ireturnedzto the 0-position and. lockedito the dividing plate .llfiiby means of the stop pin-23. After.thatptheedividing plate I5: is releasedybytheilatch l.9- beingiwitlr-; drawn.

The invention is-not limited to theexample-soiembodiment disclosed' in the drawings, a. number of deviations from this" construction sible; xI-Iereinbefore, iit was indicated aszzbein'g possible to have the workpiecestationarygnelae tively tothe machine .frameduringthe rgrinding operation and" insteadpto.causerthezlead unitzziio guide the grinding tool ,3 in :the. requisite manner: It is also conceivable .to impart; ,adinsti-ng pmov ments to the workpiece aswell .as :toatheNgrindi-l ing-tool, the latterbeing; for:instance;.;mounted in a head stock displaced rectilinearl-y duringathe grinding operation, while the work piece performs at :th -same,time therotary movement .treqnired as ,a complement; to the. rectilinear movemerit; order that the shape of the tooth shall be followed. The guide rail may be replaced by a curve deviating from the rectilinear shape, according to the shape of the edge of the work piece. Nor is the invention tied to the example of embodiment disclosed in the drawings as far as the detail constructions are concerned.

What I claim is:

1. In a grinding machine the combination with a frame, a, grinding tool carrying member, a work piece carrying spindle journalled in a movable carrier, a dividing unit comprising a pair of members mounted on said spindle and angularly adjustable with respect to each other, means for coupling said members mechanically in the desired one of a plurality of positions of angular adjustment, and means for clamping one of said members to said spindle, of a lead unit for guiding the rotary movement of said spindle, relatively to the carrier; said lead unit comprising a guide rail mounted in the frame to be set in various angular positions about an axis relatively to said frame, means for clamping said rail in a desired position of angular adjustment two-way motion-transmitting means connecting said rail to the other member of said pair of members and thereby to said spindle when said pair of members are mechanically connected by said coupling means, whereby motion may be transmitted to said spindle upon displacements of said carriage when said guide rail is clamped by said clamping means in angular position with respect to the path of movement of said carriage and alternatively angular adjustment of said guide rail may be effected by rotation of said spindle when said clamping means is released, said motiontransmitting means including a roller engaging said rail and having a neutral position in which its axis coincides with the axis of angular adjustment of said guide rail, and cooperating means on said carrier and said other member for latchingthe latter in a preselected zero position of angular adjustment with respect to said spindle corresponding to the neutral position of the motion-transmitting means. v

V 2. In a grinding machine as claimed in claim 1, the provision of aholder for the guide rail displaceable in the longitudinal direction of the frame, mounting means supporting said guide rail for sliding movement, means supporting said mounting means for angular movement on said holder, means for clamping said mounting means to said holder in a desired position of angular adjustment, and of means to lock said guide rail to said mounting means.

"3.'In a grinding machine, the invention as recited in claim 1, wherein said dividing unit members comprise a carried disk which is the member of said pair which is connected to said guide rail by said two-way motion-transmitting means, and a dividing plate having a series of circumferentially spaced openings, and said latching means comprises a latch slidably supported on said carrier and a latch-receiving opening extending through said dividing plate.

4. In a grinding machine, the invention as recited in claim 1, wherein said dividing unit members comprise acarrier disk and a dividing plate having a series of circumferentially spaced openings, and said coupling means comprises a stop pinrmounted on said carrier plate for engagement in the selected opening of said dividing plate.

5. In a grinding machine, the invention as recited in claim 1, wherein said dividing unit memhere comprise a carrier disk and a dividing plate having a series of circumferentially spaced openings; and wherein said means fortransmitting motion to the other member of said pair comprises .a gear rotatably mounted on said spindle and having a hub carrying said dividing plate, and a rack bar meshing with said gear, a roller being 'journalled on said rack bar and seated in said guide rail.

6. In a grinding machine, the invention as recited in claim 1, in combination with means for establishing a desired clearance angle for the surfaces of the work piece, said means comprising a cooperating graduated scale and fiducial mark on said carrier disk and movable carrier.

KARL WILHELM JOSEF HJELMBLAD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,603,629 Morgan Oct. 19, 1926 1,870,764 Aeppli Aug. 9, 1932 2,212,855 Chittenden Aug. 27, 1940 2,294,045 Orcutt Aug. 25, 1942 FOREIGN PATENTS Number Country Date 57,348 Switzerland Aug. 9, 1911 315,508 Germany Nov. 6, 1919 363,036 Germany Nov. 6, 1922 425,887 Germany Mar. 1, 1926 

